Induction-coil.



E. B. JACOBSUN.

INDUCTION COIL.

AI'ION mu) AP I913- 1,268,468. Patented Juno 4, 1918.

UNITED STATES PATENT OFFICE.

EDWARD B. JACOIBSON, OF PITTSF IELD, MASSACHUSETTS, ASSIGNOR TO HEN DEE MANU- FACTURING COMPANY, OF SPRINGFIELD, MASSACHUSETTS, A CORPORATION OF Patented June 4, 1918.

MASSACHUSETTS.

mUCTION-COIL.

1,268,468. Specification at Letters Patent.

Application filed December 8, 1918. Serial No. 804,532.

To all whom it may concern:

Be it known that I, Enwaao B. JAcoBsoN, a citizen of the United States, residing at Pittsfield, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Induction- Coils, of which the followin is a description, reference being had to t e accompanydrawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in induction coils, and more particularly to coils of this character used as s arking coils for an ignition system for com ustion en 'nes.

An object o the invention is to provide means in connection with the coils for directing and shortening the path of the magnetic flux so as to increase the efiiciency of the current induced in the secondary coili In the drawings which show by way of illustration one em diment of the invention,

Figure 1 is a side elevation of an induction coil embodying my improvements;

Fig. 2 is a longitudinal sectional view through the same;

Fi 3 is a sectional view on the line 3, 3 of Fig. 2.

The induction coil consists generally of a core of soft iron on which is placed a primary coil. On the outside of this primary coil is located a secondary coil. At each end of the vcore is a magnetic plate, which is extended beyond the core so as to overlap the primary coil and partially overlap the secondary coil.

Referring more in detail to the drawings, my improved induction coil as herein shown consists of a core 1, which is made up of a bundle of soft iron wires arranged side by side and extending longitudina ly of the. core.

Located on said core is a. primary coil 2, which is made up of suitable layers of mm lating material, suchms paper or the like, and a series of windings of relatively coarse wire. Outside of the primary coil 18 a secondary coil 3, which is preferably formed of a fine enamel covered wire, and this secondary coil is preferably surrounded by a rubber cover 4, which entirely incloses the coil and rotecte the same from moisture.

After t e coils have been formed or assembled, as above noted, a disk of insulat ng material 5 is placed at each end of the core, and this disk is formed with an opening 6 of substantially the same diameter as the core, and a recess 7, which extends beyond the primary coil and partiall overlaps the secondar coil. There is a isk 5 at ea c,h end of t e coils. A magnetic late 8 is located in the recess in one of t e disks and this plate carries a rod 9 which is firmly secured thereto in anydesired wa The rod 9 extends centrall through t e core. A magnetic plate 10 tting the recess 7 in the other disk is provided with an opening which extends over the rod 9. This opening is threaded and the threads in the opening cooperate with threads on the rod so that the ma etic plates also serve to hold the disks 5 1n place. The magnetic plate 8 may be provided with suitable openings through which the wires from the coils extend.

It is to be noted that these magnetic plates 8 and 10 extend beyond the primary coil and overlap the secondary coil substantially throughout its diameter. netic plate directs the flow of the magnetic flux so as to asuresaid flux passing wholly outside of the primary coil. In other words, it directs the return path of the magnetic flux so that there is substantially no return through the primary coil, which, of course, would be wasted.-

Then again, these magnetic lates serve to shorten the air gap through w ich the mag netic flux flows, and thereby increase the efl'ective current induced in the secondary coil.

The magnetic plates 8 and 10 are formed with recesses in the innerfaces thereof, to receive the core 1, whereby a more efiicient circuit is established for the flow of flux.

It is obvious that minor changes in the details of construction may be made without departing from the spirit of the invention, as set forth in the appended claims.

Havin thus described my invention, what I claim s: y

1. induction coil comprising a core, a primary coil and a secondary-coil extendin about said core, an insulating disk at cac end of the core, each disk ha a recess formed therein, a ma etic plate coated in each recess and exten ing so as to cover the primary coil and overlap the secondary coil,

each of said magnetic plates havi a recessed engagement with said coil, an means for connecting said magnetic plates.

This mag- An induction coil comprisi nlg a core, primary cciland a secondary C01 extendm about said core, an insulating disk at one so as to cover the plates having a i a rod extending centrally through said core 10 g and threaded into said magnetic plates.

11 In testimony whereof, I afiix my signature, in the presence of two witnesses.

EDWARD B. JACOBSQN. Witnesses:

CHARLES L. S I'mvhnw, JOHN D'. Smrrmm 

